Current mobile devices generally support a storage mode and a synchronization mode by a USB interface. The synchronization mode includes synchronization of an address book, a calendar, an email, a message and an application etc. with other devices. When data operations of the synchronization mode or the storage mode need to be performed, data in the mobile device may be operated just when the mobile device is connected to other devices. Therefore, there is a great security threat, and security of data in the mobile device cannot be guaranteed. For example, in a case that the device of the user is lost or the user leaves temporarily, others may damage or copy the data in the mobile device directly via the USB data line as long as they get hold of the device, even if the user sets a screen locking password.
Therefore, it is desired to solve a problem of how to maintain security of the data in the mobile device.